I need a little help about cancer diagnosis?

my dad who is 70 had a kidney transplant in 99 and has done great til recently..he was in the hospital two weeks ago for 6 days for pneumonia and while he was there getting xrays and cat scan found a malignant tumor on his old kidney he goes in two weeks to have the 7-8 cm massive mass they called it removed . .what am I looking at here and what do I prepare for after surgery possible chemo